8株产变异型CTX-M-14细菌的耐药基因分析

Drug Resistance Genes of Eight CTX-M-14 Variant Genotypes from Klebsiella pneumoniae and Escherichia coli

目的 分析本地区大肠埃希菌和肺炎克雷伯菌中产CTX-M-14型超广谱β-内酰胺酶的变异株基因序列。方 法使用通用引物经聚合酶链反应，自本地区1999～2000年间分离的确认产ESBLs 98株大肠埃希菌和肺炎克雷伯菌中分离出产CTX-M-9组的所有菌株，将PCR产物送交测序公司完成测序，提交GenBank进行比对，并作结构分析。结果 本地区的产CTX-M-14型超广谱β-内酰胺酶菌株中有8株变异株存在。结论 合肥市存在新的CTX-M型产超广谱β-内酰胺酶基因型，来自CTX-M-14。

OBJECTIVE To analyze the sequences of drug resistance genes of the novel CTX-M type of extended spectrum β-lactamases（ESBLs） in Hefei Anhui Province. METHODS A pair of primers were designed to detect the groups of CTX-M-9 by PCR from 98 strains confirmed ESBLs-producing Klebsiella pneumoniae and Escherichia coli isolated between 1999 and 2000 in Hefei, and then sequenced the productions of PCR, Compared the sequences on blast via GenBank and analyzed the molecular structure to find out whether the change in nucleotides had induced the destitution of amino acid in specific site. RESULTS Of 29 strains, 8 variant sequences of CTX-M- 14 had been discovered in several sites and resulted in the destitution of amino acid. CONCLUSIONS There are novel CTX-M types of ESBLs in Hefei, which come from CTX-M-14.